Electrical condenser



Oct. 20, 1931. P. E. GILLING ELECTRICAL CONDENSER Filed Jan. 8. 1929 FIG.

INVENTOR PR$r0N E. GILL/N6 ATTORNEY mated Oct. 20, 1931 UNITED STATES PATENT OFFICE PRESTON E. GELDIG, OI HADIDON HEIGHTS, NEW JERSEY, ASSIGNOB TO DENSEB COMPANY, OF CAMDEN, NEW JERSEY innermost RADIO concommnsna Jppllcation filed January 8, 1929. Serial No. 831,144.

This invention relates to improvements in an electrical condenser of the type used in the tuning of radio circuits.

In radio receiving sets it is quite desirable where individual condensers and dials are used for tunin the respective stages of the receiving set, t at the condenser operating dials shall all read alike when each of the circuits is tuned to the maximum point of its resonance curve. It is quite necessary to get satisfactory results that this condition exist when single dial control is used that is to say, when a plurality of condensers in different tuning circuits are operated by a single dial.

' Due to the discrepancies in the manufacture of condensers and'the variable. elements produced when installed in the receiving sets, it is ve desirable that an auxiliary balancing devlce be employed with each condenser to adjust its capacity to obtain the most efficient and maximum result.

It is therefore the principal object of my invention to provide a very sim le and inexpensive device for balancing t e capacities of the several condensers used in a receiving set, so'as to obtain the maximum efliciency from each of the tuning sta es of the same.

My invention will be rea ily understood by reference to the annexed drawings, in which Fi ure 1 is a side elevation of a tandem or doub e unit condenser having a single control with' my, compensating feature associated with each of the individual condensers.

' Figure 2 is a view takenfrom the left-hand end of Figure 1, but with a portion taken in. section on the line 2-2 of Figure 1.

Figure 3 is a section on the line 3-3 of Figure 4.

Figure 4 is a fragmentary view of a single unit condenser, the view being taken in a position similar to that shown in Figure 1, but without the rotor and control shaft.

Figure 5 is a fragmentary plan view of modified arrangement.

.45 Figure 6 is a section on the line of Fi ure 5.

eferring now to the details, wherein like numbers refer to corresponding parts in the various views, 1 and 2 are end support lates,

preferably of metal, having inturned ugs 3,;

between which extend framework strips 4 and 5,preferably of. insulating material. The end plates 1 and 2 are further held togetherby the frame members 6 and 7 which may be of any suitable material. a

Referring to Figure 1, the two groups of stator plates 8 and 9 are carried by and between the insulating strips 4 and 5. The stator plates of each group on opposite sides of the frame are carried by the r respective tie plates 10, and as shown, a floating tie plate 11 is used to anchor the lower portion of the stator plates securely in position. The rotor shaft 12 carries two groups of rotor plates 13 and 14, the group 13 cooperating with the group' of stator plates 8, while the group 14 cooperates withthe stator group 9, all in the usual manner. As shown in Figures 1 and 2, the rotor plates are partially intermeshed with their corresponding stator groups.

In order to balance up the capacity of these two condensers, I arrange on one of the insulating strips 5, a small auxiliary condenser 15 associated with the stator 8, and another auxiliary condenser 16 associated with the stator 9.

It is only necessary to explain the construction of one of these auxiliary condensers and the details thereof are clearly shown in Figure 2, wherein the auxiliary condenser 15 18 shown in section on the line 22 of Figure 1. This auxiliary condenser comprises a small plate 17, preferably having its edges 18 bent over to fit over the edges of the insulating strip 5., Two screws 19 and 20 are used for fastening the plate 17 against the strip 5.

V The screws 19 and 20 preferably have large function of helping to hold the stator group 8 by means of the tie plate 10 to the strip 5, and at the same time acting as one element of the aux iliary condenser 15. A further mountinv screw 23, isused to assist in holding the tie plate 10 to the strip 5. The other screw 20 engages one of the lugs 3 on the end is very small and may be quic by turning the screw 19 only to change the between the stator 9 and the end plate 2.

The capacity of these auxiliarylcongenserg y a uste relative distance between the heads and the plate 17. The capacity of the tuning condensers'themselves, is small, so that the capacity of the auxiliary condensers 15 and 16 is also relatively small, and this manner of constructing and mounting such compensating balancing condensers is very simple -and lnexpensive and provides a very ready means for adjusting each of the tuning condensers for the purpose described.

In Figures 3 and 4 the same general idea is disclosed. A" metallic strip 24 is fastened at both'ends by screws 25 and 26 which enter the lugs 3 on the end plates 1 and 2. The plate 17, however, in this case is the outer member of the auxiliary condenser, being separated fromthe plate 24: by means of an insulator 27. Screws 28 act to connect the plate 17 to the tie plate 10 and also to hold the tie plate 10 to the insulating strip 5. In Figures 5 and 6, I have shown an auxiliary condenser mounted to the strip 5 in a somewhat difierent manner than shown in Figure 1. In the latter construction the auxiliary condenser comprises "two plates 29 and 30 which extend ugwardly a short distance and are separated y' air, except at the point where they are mounted on the connect' strip 5. In this construction one of the plates 30 is connected to the tie plate 10 by screw 19, while the plate 29 is connected to the lug 3 1n the end plate by the screw 20. An ad justment between the plates 18 and 19 is provided by means of a screw 31 made of insulatin material. It be apparent from what has been said that the manner of mounting and connecting this auxiliary condenser between the stator and the rotor may take a number of forms, depending on thevstyle of construction of the main condenser, which ma be of any desired construction, but the one I ave shown is the construction to which I first applied my invention. 7 It will be apparent that another of the frame members may carry one of these auxiliary condensers if desired. 3

Havingthus described my invention, what I claimis: t 1. In a main tuning condenser having; end

support members fastened together b suitab e frame members, at least one of w ch is an insulator and stationary plates carried by said frame members and movable plates carried between said end support members for large-headed screw, said screw further as sistingin holding'the stationary plates to said insulator frame member said condenser being connected electrically in parallel to the main condenser.

2. In a main radio tuning condenser hav,

ing metallic end sup ort members fastened together by suitable rame members, two of which are of insulating material, and stationary plates fastened to said two frame mem' bers of insulating material, and movable plates carried between said end supportmemers for cooperation with said stationary plates: means for slightly altering" the capacity of the main condenser consisting of; a small auxiliary condenser, one element of which is mounted on one of said two frame members of insulating material, another element being art of the fastening means which holds one 0? said frame members of insulatinlg material to said end supports, while anot er element includes at least a part of said stationary plate fastening means, this last element being ad'ust'able.

In testimony w ereof, I afiix my si ature.

PRESTON E. GILL NG. 

